FLUID PHASE EQUILIBRIA
·
2022
·
IF 2.745
Yingying Huang,Chuanjun Wu,Ying Chen,I-Ming Chou,Lei Jiang
Diffusion coefficients of hydrogen sulfide in water and brine are critical in geology and chemical industries for hydrogen sulfide geological storage and hydrogen sulfide separation from natural gas. However, previous studies have mostly measured the diffusion coefficient of hydrogen sulfide in water at room temperature and normal pressure and the diffusion coefficient of hydrogen sulfide in brine had not been reported. In this study, ratio of the Raman signal intensity of the H-S bond of hydrogen sulfide to the H O bond of water, H R H 2 S / H 2 O , was used to measure the diffusion coefficients of hydrogen sulfide in water at 0.1–2 MPa and 273.1–373.1 K and in four brine solutions (0.62, 1, 2, and 3 mol•kg −1 NaCl) at 1 MPa and 273.1–373.1 K. Results showed that the diffusion coefficient of hydrogen sulfide in water increased with the increasing temperature and was insignificantly affected by the pressure, which follows the relationship derived from the Speedy–Angell power-law: D ( c m 2 / s ) = 13.013 × 10 − 5 [ T / 216.478 − 1 ] 1.974 , where T is in the temperature (K). In brine, the diffusion coefficient of hydrogen sulfide also increased with the temperature and was clearly inhibited by salinity, which can be described using the Ratcliff–Holdcroft model D ( c m 2 / s ) = 13.013 × 10 − 5 ( T / 216.478 ) 1.974 ( 1 − 0.0755 C s ) , where Cs is concentration of NaCl in brine (mol•kg −1 ).
研究领域:
地质学
·
化学工程
✓ 已验证
DOI
高影响因子
Journal of Magnesium and Alloys
·
2023
·
IF 17.6
Xiang Zhou,Haotian Guan,Heng Lu,Yangfan Lu,Jianbo Li,Jingfeng Wang,Yu'an Chen,Qian Li,Fusheng Pan
While early transition metal-based materials, such as MXene, has emerged as an efficient catalyst for the Mg-based hydrogen storage materials, their strong interaction with hydrogen resulted in the high hydrogen diffusion barrier, hindering further improvement of catalytic activity. A MXene is characterized by rich anionic groups on its surface, significantly affecting electronic and catalytic functionalities. Using Nb 2 C T x as an example, we herein illustrate the critical role of anionic T x defects on controlling hydrogen dissociation and diffusion processes in Mg-based hydrogen storage materials. The hydrogen desorption properties of MgH 2 can be significantly enhanced by utilizing T x controllable Nb 2 C T x , and it can release 3.57 wt.% hydrogen within 10 min under 240 °C with the reduced dehydrogenation activation barrier. It also realized stable de/hydrogenation reactions for at least 50 cycles. DFT studies combined with kinetic analysis revealed that the catalyst‒hydrogen interaction could be systematically controlled by optimizing surface T x defect density, accelerating the hydrogen dissociation and diffusion processes at the same time. These results demonstrate that the T x defects serve as the effective catalytically active centers of Nb 2 C T x , offering a flexible catalyst design guideline.
研究领域:
材料科学
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能源化学
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纳米技术
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表面科学
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催化化学
✓ 已验证
DOI
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2023
·
IF 6.2
Lihua Guo,Guoqiang Wang,Feng Zhang,Linyuan Lu,Bin Luo,Hongtao Huang,Jun Lin
The fissile fuel loss in tungsten (W) based ceramic-metal (Cermet) element used in nuclear thermal propulsion is of great importance. In this study, the W-Y 2 O 3 composite matrix was manufactured tentatively by Spark Plasma Sintering (SPS) to relieve the fuel loss. Performance evaluation of hydrogen (H 2 ) permeation and diffusion behaviors in the matrix was carried out by a gas permeation device. The results indicate that the diffusion coefficient of H 2 in the pure W matrix is nearly 10 times larger than that in the W-Y 2 O 3 matrix at a test temperature of 823 K. Based on the results, a careful investigation of the fuel loss mechanism of the Y 2 O 3 dispersed W matrix was performed. SEM and TEM showed that the fine Y 2 O 3 particles are distributed along grain boundaries of the W ternary-phase and present a distinct transition region of about 10 nm between the Y 2 O 3 and W phases. In particular, the crystallographic orientation relationship suggests that a semi-coherent structure is formed at the W/Y 2 O 3 phase interface : (0 1 −1) W || (1 0 −1) Y 2 O 3 and [0 1 1] W || [1 1 1] Y 2 O 3 . This semi-coherent structure is favorable for binding the two phases together tightly, thus hindering the inward diffusion of H 2 greatly. Moreover, the improved density and refined size of the W grains are achieved. Therefore, there is no doubt that the dispersion of Y 2 O 3 is beneficial for lowering the H 2 diffusion rate in the W matrix and thus reducing the fuel loss effectively. This work furthers our understanding of the key role of Y 2 O 3 in the W matrix used in nuclear thermal propulsion.
研究领域:
材料科学
·
核能工程
✓ 已验证
产品关联
DOI
高影响因子
Physica Status Solidi-Rapid Research Letters
·
2022
·Vol. 16
·期 6
·2100649
·
IF 3.277
Guoqiang Yu,Can Liu,Haiqi Gao,Tao Wang,Xiaoping Wu,Ping Lin,Lingbo Xu,Can Cui,Xuegong Yu,Peng Wang
Niobium oxide (Nb 2 O 5 ) films can provide excellent passivation for crystalline silicon (c-Si) surface after postdeposition annealing, however, its kinetic behavior and mechanism have not been explored. Herein, it is demonstrated that surface passivation by solution-processed Nb 2 O 5 films can be activated by low-temperature annealing (<200 °C) within several minutes, with the activation energy of 0.40 and 0.57 eV for hydrofluoric acid (HF) and RCA pretreated surfaces, respectively. Moreover, passivation is deactivated by higher-temperature annealing (>350 °C), with the deactivation energy of 0.86 and 1.06 eV for HF and RCA pretreated surfaces, respectively. The results combined with surface-sensitive X-Ray photoelectron spectroscopy (XPS) measurements indicate that the passivation kinetics of Nb 2 O 5 on the surface of c-Si are strongly related to the diffusion of hydrogen into and out of the Nb 2 O 5 /c-Si interface.
研究领域:
材料科学
·
半导体物理
✓ 已验证
产品关联
DOI
高影响因子
JOURNAL OF COLLOID AND INTERFACE SCIENCE
·
2025
·
IF 9.7
Fang Liu,Jiali Wang,Wei Chen,Xiaoying Zhang,Shengting Li,Jinping Li,Yu-Fei Song,Jinfeng Chu,Guang Liu
Magnesium hydride (MgH 2 ) is broadly deemed as one of the most prospective solid-state hydrogen storage materials. However, its large-scale application is hindered by several drawbacks, including an excessive dehydrogenation temperature (>300 °C), sluggish kinetic behavior, and inevitable agglomeration and growth during cycling. To address these challenges, two-dimensional few-layered laminated titanium carbide catalyst (FL-Ti 3 C 2 T x ) was synthesized via LiF/HCl etching followed by liquid-phase ultrasonic exfoliation. These FL-Ti 3 C 2 T x nanosheets exhibit efficient catalytic activity for MgH 2 hydrogen storage. The incorporation of 5 wt% FL-Ti 3 C 2 T x significantly reduces the initial dehydrogenation temperature of MgH 2 from 325 °C to 199 °C, while enabling the dehydrogenated sample to reabsorb hydrogen at room temperature. The MgH 2 + 5 wt% FL-Ti 3 C 2 T x composite demonstrates remarkable kinetic performance, releasing 6.5 wt% H 2 within 8 min at 300 °C and uptaking 5.49 wt% H 2 within 1 min at 100 °C. Even after 50 cycles of consecutive dehydrogenation and rehydrogenation, the composite retained a hydrogen storage capacity of 6.90 wt%, corresponding to a 95.30 % capacity retention rate. Microstructure analysis and theoretical calculations reveal that the unique lamellar morphology of FL-Ti 3 C 2 T x not only provides abundant active sites and hydrogen diffusion paths, but also effectively suppresses the agglomeration and growth of Mg/MgH 2 matrix during the hydrogen absorption and desorption. More importantly, the in-situ formed Ti/TiH 2 functions as a “hydrogen pump” accelerating hydrogen diffusion, prolonging the Mg H bond length, and weakening the interaction between Mg and H. These factors synergistically enhance the absorption/desorption kinetics of MgH 2 .
研究领域:
储能
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材料科学
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纳米技术
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氢能
·
催化
✓ 已验证
产品关联
DOI
PubMed
高影响因子
JOURNAL OF ALLOYS AND COMPOUNDS
·
2013
·
IF 2.39
H. Wang,J. Zhang,J.W. Liu,L.Z. Ouyang,M. Zhu
The addition of NaH by ball milling is shown to greatly improve the hydrogen storage properties and the hydrolysis properties of MgH 2 , which is related to the formation of ternary hydride NaMgH 3 with specific perovskite structure. The MgH 2 –10%NaH mixture exhibits better hydriding and dehydriding kinetics than the MgH 2 –10%LiH mixture, in which the LiMgH 3 with perovskite structure could not be formed. The catalytic role of NaMgH 3 is attributed to fast hydrogen mobility in the perovskite structure, which provides fast hydrogen diffusion pathways for the hydriding and dehydriding of MgH 2 . The NaMgH 3 also shows fast hydrolysis reaction kinetics without any passivation. Our work shows that such perovskite-type hydride demonstrates great potential as efficient catalysts for the high-capacity hydrides for whether reversible or irreversible hydrogen storage.
研究领域:
材料化学
·
无机化学
·
能源材料
·
氢储能
·
固态储氢
✓ 已验证
DOI
高影响因子
JOURNAL OF SOLID STATE CHEMISTRY
·
2025
·
IF 3.5
Xi Wu,Fei Ruan,Fenglong Zhang,Zhe Ren,Chonggui Lei,Yuwei Ma,Gaofei Pan,Weixiang Shang,Hongxia Li,Qingchun Wang,Jinxiao Bao
To study the electrochemical performance of aluminum doped CaHfO 3 proton conductors in more detail, the CaHf 1- x Al x O 3-δ ( x = 0.02,0.04,0.06,0.08) solid electrolytes were prepared by high-temperature solid-state method at the temperature of 1873K for 10 h. The XRD, SEM and EDS were used to test the phase structure and micro-morphology of the solid electrolytes, the Archimedes method was used to measure the density of the electrolytes, and the electrochemical workstation was used to test the performance of the electrolytes. The conductivity of the electrolytes in hydrogen, oxygen and water vapor atmospheres at 973–1373 K were measured by two-electrode AC impedance spectroscopy method, and the conductance activation energy of the electrolytes in different atmospheres were estimated based on Arrhenius' law. The H/D isotope effect of solid electrolytes were measured at 973–1273 K in H 2 and D 2 atmospheres, and the chemical diffusion coefficient and self-diffusion coefficient of hydrogen in the electrolytes were determined based on Fick's second law. The primary conducting carriers in different temperatures and atmospheres were revealed based on the conductivity test results. This study of aluminum-doped calcium hafnate electrolyte may provide reference for the research and development of calcium hafnate based proton conductors.
研究领域:
材料科学
·
电化学
·
固体物理
·
能源材料
✓ 已验证
产品关联
DOI
高影响因子
危险品化学品经营许可证（带存储）